Latest Papers

ASME Journal of Mechanisms and Robotics

  • A Small-Scale Integrated Jumping-Crawling Robot: Design, Modeling, and Demonstration
    on June 16, 2025 at 12:00 am

    AbstractThe small jumping-crawling robot improves its obstacle-crossing ability by selecting appropriate locomotion methods. However, current research on jumping-crawling robots remains focused on enhancing specific aspects of performance, and several issues still exist, including nonadjustable gaits, poor stability, nonadjustable jumping posture, and poor motion continuity. This article presents a small jumping-crawling robot with decoupled jumping and crawling mechanisms, offline adjustable gaits, autonomous self-righting, autonomous steering, and certain slope-climbing abilities. The crawling mechanism adopts a partially adjustable Klann six-bar linkage, which can generate four stride lengths and three gaits. The jumping mechanism is designed as a six-bar linkage with passive compliance, and an active clutch allows energy storage and release in any state. The autonomous self-righting mechanism enables the robot to self-right after tipping over, meanwhile providing support, steering, and posture adjustment functions. Prototype experiments show that the designed robot demonstrates good motion stability and can climb a 45 deg slope without tipping over. The robot shows excellent steering performance, with a single action taking 5 s and achieving a steering angle of 11.5 deg. It also exhibits good motion continuity, with an average recovery time of 12 s to return to crawling mode after a jump. Crawling experiments on rough terrain demonstrate the feasibility of applying the designed robot in real-world scenarios.

Singularity Loci, Bifurcated Evolution Routes, and Configuration Transitions of Reconfigurable Legged Mobile Lander From Adjusting, Landing, to Roving

Abstract

This paper presents the reconfigurable legged mobile lander (ReLML) with its modes from adjusting, landing, to roving. Based on the invented metamorphic variable-axis revolute hinge, the actuated link has three alternative phases of rotating around either of two orthogonal topological axes or locking itself to the base as a rigid body. This property enables the ReLML to switch among three modes and within two driving states (as the adjusting and roving modes are active mechanisms driven by motors, while the landing truss is regarded as a passive mechanism driven by the touchdown impact force exerted on footpad). The unified differential kinematics for the ReLML is established by the screw-based Jacobian modeling, unifying both active and passive operation phases throughout all modes. Afterward, the distributions of workspaces and singularity loci in three modes are discussed for the multi-solution sake, and the selection principle of the practicable solution pattern is proposed to obtain the actual workspace, singularity loci, and configurations. The results stemming from the Jacobian-matrix-based method and the Grassmann-geometry-based method give mutual authentication. Finally, as prospects for promising applications, four bifurcated evolution routes and configuration transitions are figured out and compared.
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